had a bad experience with Midas, although with another car. Midas offer a lifetime replacement for mufflers and yes, they will replace the muffler but will charge for labor and other pipes which will coincidentally needs immediate repair. In other words, Midas will hit you somewhere else, one way or the other. Yep, nothing is free!!
my MB muffler was replaced by my mechanic at CDN$500 parts (OEM) and labor.